German Patent DE 4,209,914 is of interest. There is shown in this German patent an assembly including a swiveling body having a plain bearing bushing and a ball bearing for the clamping roll mounted on the lateral surface of the swiveling body. In instances where the swiveling body is made of plastic, the mounting of the bearing is usually not sufficient to survive the required service time without damage. Further, it is required to fix the bearing in place axially on both sides. This requires an additional work step as well as fastening parts are required. The same is also true for the sliding bushing, which is not described in detail.
With the foregoing in mind, it is an object of the present invention to improve the clamping device described above in such a way that it can be produced very simply. Further, the device is characterized by novel features of construction and arrangement so that the bearing can be permanently held in place axially in the plain bearing bushing or sleeve. To this end, in accordance with the present invention, the edges of the bearing bushing or sleeve which is wound out of a strip are joined to each other in the area of the butt joint under intrinsic tension. In accordance with the present invention, the lateral surface of the bearing bushing and the bore surface of the rolling bearing function as parts of a mold for forming the swiveling body by an injection-molding process.
The present invention provides several advantages over the prior art. For example, since the rolling bearing and the plain bearing and the bearing bushing function as part of the mold used to injection-mold the swiveling body, production is a single-step process apart from fabrication of the rolling bearing and the bearing bushing. Further, these two components can be fixed axially in place simply by appropriate positive-locking elements, which are formed simultaneously during the injection-molding process. The bearing bushing is made at low cost by winding and is dimensionally stable even under the action of temperature changes and the force acting on it during the injection process. The edges, which are free in the circumferential direction, lie under pretension on one another so that the liquid injection material cannot intrude between them. As a consequence of this feature, the sliding bushing retains its precise dimensions even after fabrication.